The Research On Self Adaptive Fuzzy PI Control Strategy Of PMSM Servo System

The PMSM servo system has several issues,nonlinear control,time-varying parameters,load disturbance,etc,while existing PI control strategies cannot trace parameters and have no robust resistance to load disturbance ideally,so that it is restricted to a great extent.Therefore,this paper assumes a solution to handle these issues.Here is the conceiving process:At first,based on the analysis of the mathematical models of Permanent Magnet Synchronous Motors(PMSM)created under different coordinate systems,calculated the electromagnetic equation respectively,this paper uses(28)0di vector control to get the fuzzy control rules on the speed loop control of PMSM servo systems through a refining of expert knowledge,and designs a kind of PI controller integrated with fuzzy control rules,so as to be less dependent on the precision of the mathematical models of the controlled objects,and improve the system's performances on tracking load changes and adapting to parameters.At first,create an SVPWM-based servo system model through Matlab/Simulink,launch it at a lower given speed,to verify the feasibility of the concept through simulation,so the conclusion vertify that: when under a lower given speed,fuzzy PI controllers can effectively eliminate overshoot,improve system robustness,and enhance the adaptability of the system to load changes.And then introduced a self-adaptive mechanism on the basis of fuzzy PI controllers,so as to further improve the static and dynamic performance of fuzzy PI controllers based on the model constructed,offsetting the shortcoming of limited performance when the fuzzy PI controllers are at a higher given speed.The self-adaptive mechanism bases its design on the original fuzzy PI controllers,but has different parameter output and uses a new rule library.Launching it at a higher given speed and make a simulation verification on the original system model again to test the effect of this plan,and finally the conclusion vertify that: the introduction of self-adaptive fuzzy PI controllers during system launching can reduce overshoot and enable the system to be more stable when entering the steady state,and to return to the steady state more quickly after a sudden increase of load.Made a significant improving on the overall performance of system at last.Finally,position loop is added to initial system,three closed-loop servo system is constructed,the application of adaptive fuzzy PI algorithm to position is discussed,thedominant position of P adjustment is kept and the focus is decrease the output of I parameters to get new rules library;The simulation result suggested that the application of adaptive fuzzy algorithm to position loop can effectively improve the ability of system to trace rotator and resist to disturbance.